DARPA's Next Generation (XG) program goals are to develop enabling
technology and system concepts to dynamically redistribute allocated
spectrum along with novel
waveforms in order to provide dramatic improvements in assured military
communications in support of a full range of worldwide deployments
(see XG home page at HTTP://www.darpa.mil/ato/programs/xg/).

SRI is sole performer on the XG Policy Control project described below.

The vision of radically increased spectrum usage through XG-enabled
radios requires regulatory bodies and spectrum holders to be convinced
that the radios will follow rules and policies. This project will
develop an expressive and extensible policy language with executable
semantics, for describing policies that meet the needs of a wide variety
of spectrum regulation bodies. We will also develop efficient reasoning
algorithms to reason about policy compliance during radio operation.

The main innovations of the proposed approach include

An expressive and extensible policy language with executable
semantics, for describing policies that meet the needs of a wide variety
of spectrum regulation bodies, and for supporting policy reuse and
efficient reasoning via a disciplined use of multiple inheritance class
structures and meta-policies.

A policy conformance algorithm that checks the compliance of
candidate transmissions using efficient, state-of-the-art rewriting
technology. The design of the algorithm is independent of, yet easy to
integrate into, any radio design, to encourage competitive,
best-of-breed XG radio development.

A capability to search for transmission candidates if the radio
makes an underspecified, unbound transmission request, using fast
decision procedures that yield candidate parameter bindings for
satisfiable policies. This can considerably increase the use of existing
spectrum opportunities of which a radio is not aware.

The policy language and the reasoning algorithms will be
designed to be robust in the presence of conflicts as well as the
absence of complete information.

Policy authoring concepts for creating and visualizing policies,
exploiting the complex inheritance relations to structure a policy set
and providing Web-style templates that are easy to use for the domain
specialist.